After returning from his journey to seek the Dharma in Tang China, Enchin petitioned the Imperial Court for the issuance of an official kugen certificate (proof) of Dharma transmission, following the examples of his predecessors Saicho and Gishin. Two copies of this document exist: a draft copy dated March 7, 863, and a copy written by Enchin dated November 13 of the same year. The draft, comprising two drafts pasted back to back on one volume, has the first draft (initial draft) on the back and the second draft, revised based on the initial draft with additions and corrections by Enchin, on the front. The final copy is almost identical to the revised draft and was submitted. It details the entire process from the beginning of the journey to Tang China through to his return, serving as a fundamental historical document for understanding Enchin's journey.